REQUEST: make empty fields somehow stand out

I would like to propose an option for the user to have all or some specific fields somehow stand out if they are empty for the selected single file; or in case of a group of files, if at least one of them does not have any data [while the others have some]

This could be indicated with changing of the white box to a gray one. Or with a name of such box displayed in red instead of the standard black. Or by drawing thick RGB 0-255-0 [bright green] frame around the white box. Color [maybe defined by the user at least to some extent] and the [exact] form is a matter of further discussion

This would be handy for people like me who always for example put a YEAR and DISCNUMBER; and also put something like a dot [or some other pre-chosen sign] when they do not have proper data [to distinguish such a file from a one for which such work simply was not done or was somehow un-done]. An indicator would clearly remind us to work on such mandatory fields when, especially when adding new stuff which has cleared out fields

With one or two fields you can remember this on your own. But right now I have 5 mandatory fields [used to have 6] plus 2-3 that are required to be filled in some cases. And my empirical long time data shows that I constantly somehow forget [glance over] some of the mandatory fields, leaving them empty. If I saw some distinct color / object, then I would have to be really tired or in hurry to not to notice it [and do the necessary tagging]

Just a reminder:
There are no empty tag fields. Either you have data in a field or it is not stored in a file, it does not exist in that file then.

MP3tag does not compare files. So it cannot tell that a file is different in comparison to other files.

Just under the assumption that some kind of highlight would be possible: It is not clear what should happen if the difference in tag fields appears in fields that are not displayed but are only obvious in the extended tags dialogue.

Point taken

If the Tag Panel [and maybe Columns also] would simply grey or black out empty fields that are turned on, then what would be the problem. What Tag Panel / Columns would not currently see [show to user] then Mp3ag would not have to think how to interpret that and in what way present

Just a simple rule: you have a field in Tag Panel and mark it as relevant - then show the user some indication when it is empty

I'm not going to add this feature. You can use a custom Filter to have the file list reduced to files where specific fields are missing.

Not even as a option, that would have to be turned on first and defined [which fields]?

I am sorry to hear that

But that is a neat workaround; although it will require from me remembering to use it every time I add new files [as opposed to just seeing empty fields stand all of the time], and semehow paste it a it will be quite long

And so by using a filtering expression like for example

I will be able to narrow those who did not get the original artist or composer info